First particle identification with a Disc-DIRC detector

The PANDA experiment at the future FAIR laboratory at GSI in Darmstadt, Germany, will require excellent particle identification for its study of proton–antiproton reactions in the few GeV energy range. In the confined space of the PANDA Target Spectrometer, two RICH-type Cherenkov detectors mainly aim at pion–kaon separation: a Barrel-DIRC detector patterned after the BaBar-DIRC covering the central angles and a Disc-DIRC detector for the forward theta angle range from 5° to 22°. Such a Disc-DIRC design has not yet been used in particle physics experiments. A demonstrator prototype, one quarter segment scaled to 80% of the PANDA geometry, constructed at Giessen university and equipped with 480 sensor pixels, has measured particles of several GeV/c in a secondary mixed beam delivered by the PS T9 test beamline at CERN in October 2012. A first analysis of the recorded hit patterns is presented. -- Highlights: •Our goal is charged particle identification for the PANDA experiment at FAIR. •We constructed a Disc-DIRC Cherenkov detector demonstrator prototype. •We tested the Disc-DIRC detector in the mixed beam of the CERN PS T9 beamline. •For the first time particle identification with a Disc DIRC was demonstrated